COM Exception Could not open IPM Subtree.Check Profile Privileges

[lfasci]

I'm trying to migrate from exchange Version: 6.5.7226.0 on Microsoft Server 2003 for Small Business to ZCS 5.0.7. The windows platform locale is english while the one zimbra is Italian.
I installed a windows xp SP3 workstation with Outlook 2003 SP1 (all italian)
I created an AD account for migration and logged on the WS
I configured this account on outlook 2003.
I changed the mailbox rigths for the accounts I want to import as shown in the attached image.
Then I tried to run ZCSExchangeMigrationWizard-5.0.7_GA_2450 on the XP workstation but I receive this error in the log:
Error while importing mailbox xxxxxxx@yyyyyyyyy.it: COM Exception Could not open IPM Subtree.Check Profile Privileges.
I added the user to the domain's administrators but I receive the same
error message.
If I try to read the mailboxes from outlook I can see the others account maiboxes without problems.

What could be wrong ? Can you help please ?

Thank You very much

[lfasci]

I upgraded to zcs 5.0.8 and tried to use ZCSExchangeMigrationWizard-5.0.8_GA_2458 but with the same result.

Is this a bug ?